This invention relates to concrete forming systems, and more particularly to an improved system for fabricating concrete floors.
At the present time, concrete floors for buildings and the like are often fabricated utilizing forms or pans having an inverted U-shaped cross-section. The forms are positioned adjacent one another on wooden shoring members, and concrete is poured over the forms. The uppermost portion of the resulting concrete structure forms the floor per se, while the portions of the concrete structure extending between the forms comprise floor supportive beams. Following the concrete forming operation, the shoring members and the forms are disassembled and are stored for reuse.
This type of concrete forming system has proven to be both practical and economical, and has therefore gained relatively wide-spread acceptance. However, notwithstanding the commercial success of the process, a number of problems have been encountered in its use. For example, the forms which are presently commercially available are supported on the shoring members in such a way that the distance between the tops of the forms and the shoring members is fixed. This in turn means that the height of the beams of the resulting concrete floor structure is also fixed. It is therefore necessary to provide a different set of forms if a different beam height is desired. This is not only costly from the standpoint of purchasing the forms, but also from the standpoint of storing the different sets of forms between uses.
Another problem that is involved in the use of the forms that are presently available commercially relates to the fact that the forms are adapted to be joined together by fitting the end of one form over the end of the next adjacent form. The resulting joint between the forms may be considered as a lap joint and is unsatisfactory due to the fact that it forms a ridge in the resulting concrete structure. Also, concrete tends to flow into the space between the two forms during operation. In certain instances this can lead to difficulty in disassembling the forms.
Problems have also been encountered with respect to the shoring members that are utilized to support the forms. At the present time an undue amount of lumber is required in order to fabricate the shoring members. This is costly, both from the standpoint of initial costs and from the standpoint of storage costs. Also, the wooden shoring members utilized in presently available concrete forming systems are not readily adapted to stacking, leading to additional difficulty and expense with respect to storage of the shoring members.
The present invention comprises a concrete forming system which overcomes the foregoing and other disadvantages long since associated with the prior art. In accordance with the broader aspects of the invention, there is provided a plurality of forms each having a substantially planar upper wall extending to curved shoulders at each edge. Side walls depend from the curved shoulders and comprise upper outwardly tapered portions to facilitate removal of the forms following a concrete forming operation and lower portions extending perpendicularly to the upper wall and parallel to each other. Longitudinally spaced sets of holes are formed in the side walls, with each set including at least two vertically spaced holes formed in the lower portions of the side walls. The forms are secured to wooden shoring members by means of fasteners extending through the holes in the side walls, with the positioning of the upper walls of the forms relative to the shoring members depending on the particular hole of each set that receives the fastener. The fasteners preferably comprise double-headed nails to facilitate subsequent disassembly of the forms.
In accordance with other aspects of the invention, each form has a lip extending from one end thereof. The lip extends along the inner periphery of the upper wall and the side walls of the form, and is adapted to receive and support the opposite end of an adjacent form. There is thus provided a butt joint between adjacent forms which is advantageous in that it does not result in a ridge in the resulting concrete structure, and further in that it provides concrete from flowing into the space between the forms.
In accordance with still other aspects of the invention, the forms are supported on shoring members comprising wooden stringers extending between adjacent forms. The stringers have longitudinally spaced apertures formed therein. The stringers are in turn supported by post shores which are adjustable as to height. The post shores have locating pins extending from the upper ends thereof which are received in the apertures of the stringers. This not only facilitates assembly and disassembly of the shoring members, but also accommodates stacking of the shoring members between uses.